/**
 * #      996
 * 名称   正方形数组的数目
 * 链接   https://leetcode-cn.com/problems/number-of-squareful-arrays
 * 题解   [72](https://leetcode-cn.com/problems/number-of-squareful-arrays/solution)
 * 通过率 48.5%
 * 难道   困难
 */

